1. Field of the Invention
The present invention relates to a tread exercising machine, and more particularly to a tread exercising machine that can be used to perform the exercising action of mountain climbing and walking.
2. Description of the Related Prior Art
The closest prior art of which the applicant is aware is disclosed in the Taiwanese Patent Application serial No. 89214245, entitled xe2x80x9cMOUNTAIN CLIMBING MACHINExe2x80x9d. In the patent application, the mountain climbing machine comprises two opposite side plates 10, and a plurality of steps 20 mounted between the two side plates 10. Each side plate 10 defines a guide groove 11 whose outer periphery is provided with a guide plate 12. Each side plate 10 has two ends each secured with a bearing seat 13 for insertion of a bearing 131. A drive shaft 50 is mounted between two bearings 131. The drive shaft 50 has two ends each respectively combined with a drive wheel 30 which is rotated by a drive motor 40. Each step 20 has two ends each mounted with a linking shaft 21 and a guide rod 22. The linking shafts 21 of each step 20 are connected by a connecting rod 211 so that the steps 20 are connected with each other. The linking shaft 21 is driven by the drive wheel 30. The guide rod 22 of each step 20 has an outer end received in the guide groove 11 of the side plate 10, so that each step 20 can be moved along the track of the guide groove 11, whereby the steps 20 are moved downward from the upper position of the side plates 10, such that the user can tread the steps 20 to move upward, thereby forming the exercising action like climbing the mountain.
The primary objective of the present invention is to provide a tread exercising machine that can achieve the exercising effects of climbing the mountain and walking.
Another objective of the present invention is to provide a tread exercising machine, wherein each step can be linked and moved fluently.
In accordance with the present invention, there is provided a tread exercising machine comprising: two parallel symmetrical side walls, a plurality of serially arranged steps that may produce predetermined recycling action, and a housing mounted on the two side walls, wherein,
each of the two side walls has one opposite side pre-fit with a cam groove and a chain guide groove each having a symmetrical track, each of the two side walls has two opposite ends pivoted with a shaft, each shaft is respectively secured with a sprocket located adjacent to an inner side of the side wall, a chain is mounted between two opposite sprockets, the chain is inserted into the sprocket guide groove of the side wall;
each of the steps has two end faces each provided with a protruding shaft and a retaining shaft respectively, the protruding shaft has a free end secured with a bearing, the bearing is inserted into the cam groove of the side wall to form a rolling state, the retaining shaft has an end portion combined with the chain at a position with a preset span, the two chains are driven by a driver, so that each of the steps produce a predetermined movement with the track of the cam groove and the chain guide groove, thereby forming a stepwise slope region, and a smooth platform region.
The chain guide groove is formed with a flange extended toward a bottom edge of the chain, and the bottom edge of the chain is rested on the flange.
Each of the steps has a surface provided with a plurality of transversely extended insert blocks and recesses so that the steps can be inserted with each other, and the housing defines a plurality of recesses at predetermined positions so that the insert blocks on the surface of the steps are inserted into and slide in the recesses of the housing.